21071161736 has 32 divisors (see below), whose sum is σ = 40879776600. Its totient is φ = 10170048000.

The previous prime is 21071161733. The next prime is 21071161789. The reversal of 21071161736 is 63716117012.

It can be written as a sum of positive squares in 4 ways, for example, as 10627548100 + 10443613636 = 103090^2 + 102194^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21071161696 and 21071161705.

It is not an unprimeable number, because it can be changed into a prime (21071161733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1617746 + ... + 1630718.

Almost surely, 2^21071161736 is an apocalyptic number.

It is an amenable number.

21071161736 is a deficient number, since it is larger than the sum of its proper divisors (19808614864).

21071161736 is a wasteful number, since it uses less digits than its factorization.

21071161736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20009 (or 20005 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 35.

Adding to 21071161736 its reverse (63716117012), we get a palindrome (84787278748).

The spelling of 21071161736 in words is "twenty-one billion, seventy-one million, one hundred sixty-one thousand, seven hundred thirty-six".